To be clear, I'm aware that the Honda VTEC system operates in a much different way than the Hemi engine. I was simply pointing out that variable cam timing technology has been around for awhile. Appreciate you watching!
Honda used to swap to an entirely different camshaft lobe during vtec operation. By doing that you can flip both valve duration and timing to another set parameter. Now honda uses I-Vtec which also incorporates a camshaft actuator to twist the camshafts independent from the crankshaft using oil pressure. Also on the honda j series 3.5/3.7 honda uses the same vtec setup but instead of swapping to a more aggressive camshaft lobe they shut down the back bank of the engine and run in a cylinder deactivation mode. Honda does a trick with the motor mounts to cancel out the vibration the driver/passengers feel when running just 3 cylinders.
really!! you're a dodge tech ( im not im a caddy's/Chevy and DSM/aftermarket tech, with a 2G-hemi+Tr6070/charger and k1500-1980's ownership, also a millwright/maintenance ) and forgot the cam-in-cam 4th and 5th gen vipers ( working on copying/modification this for my big block 440/hemi, and yes i own a 4th gen viper cam core and yes it's a 2-peace unit with 9-40* of movement between the lobes, hydraulic+ecu/plc powered/controls, going back the the 1960's holly/chevy and the 350/sbc had a aftermarket phaser-option for cintrifical-operated/springs-operated VVT and or cable-dashboard-operating but you also didn't mention that 🤔 ) engine? variable lobe angles aka LSA is possible and the hemi/3d-G was planning for getting the same technology as the vipers but for some reason hasn't happened yet on the twin-phaser assembles also heard rumours of the multi-air VLL+VVT+LSA also being added to the v8's but also hasn't been sofar 🤞 it does happen to it can out do the coyote/ford's platform with " cam on demand " lost me as you made it sound like ford's/imports got the "hot-stuff" and USA 🇺🇸 can't do it with the cam in the valley/single-camshaft-tunnel design aka only one way, and no my 2C coyotes are heavyweight and or can do without the 3 extra cam's & *phasers* but that's my take and my ford-friend doesn't agree and likes the voodoo 😉 better job 👍 on explaining the oiler-port's ( missed the opportunity for mentioning how similar it is to the oil pump's used in newer products ie godzilla/ford's ect as a vain-pump ) as my first time being experience 2006-14 era with phasers wasn't explained very useful to me and i thought* the bottom sprocket moved the chain or the gide's changed positions, and yes some do use that method but not common to see and or limited adjustment can be made ect aka the way vipers ( my engine use's a gear-drive just as a point that chains-oiled aren't the only design possibility's, as a dry belt is used on the 2JZ/imports, anyways im a industrial/diesel/gear-built guy 😉 ) do it is the smarter choice but really should have used a extra pumping as variable-engine-RPM 20psi~ ( versa's constant 200-1200psi normally found in lightweight* hydroelectric system's, the newer version's using full electronics is debatable as power is limited but dynamic-speed is quicker ) and high rpm/loads and or big cam's/lift can tax the system to much making erratic operating ect
This is probably the clearest, most succinct description of variable valve timing I've come across - I'd had maybe a rough idea of how it worked beforehand, but I came away from your explanation with a much firmer understanding of both the mechanism and the underlying idea. Thanks for a great video. 👍
Lobe separation angle relates to VVT? Didn't realize you were still creating content, very cool. I need to binge watch your channel...lol Still in my 2021 Challenger Scat, still running like a top.
Outstanding videos. I learned a LOT from you today, not only this video but MDS and the dreaded P0305 code issue which I currently have on my 2011 RAM.
I really enjoyed this video. What a great educational video explaining VVT. I didn’t know how VVT worked, but now I know. Thank you so much. I would love to see more educational videos like this with regard to Dodge Hemi vehicles. 👍
@@ReignitedAuto please mention the cousin's as-well in the dodge lineup with the tiger-shark engine as the general concept isn't terrible for both i just see the ( liquid push rod's and jerk-pump's ) fiat-design is a better idea for v8 street cars as VLL and cylinder deactivation on a skiping firing order is possible vs MDS that historically is the same 4 cycling cylinder's / bank and can lead to more where+oil being used/burt idling and or long hot freeway running yes some see it as a boogie man but i like keeping my MPG up under lower loads ect and maybe some lower/longevity between rebuild's
This is great technology. It helps the engine produce so much more power without any side effects. Between this and the variable runner length intake my truck has it feels like I'm always in the torque curve when I'm pulling. Great explanation on how the system works.
I remember back in the late 70s, I had an Olds Cutlass with the 455 engine. I decided to rebuild the engine and I went to my local speed shop to get the tried and true Cloyes double-roller gears and chain. But they got a new product in made by a different company where the upper cam gear had these huge springs built into it. My cam I was using (Isky performance cam) was going to be quite bad on vacuum and since my Cutlass has power brakes, this was going to be iffy at best. This spring loaded cam gear was supposed to adjust valve timing at low speeds so I had enough vacuum for braking, but gave me advanced timing for performance at WOT. I had a lot of fun with that cam gear and found that it was possible to adjust limits on the automatic timing adjustments using only an allen key. I cut my timing cover in half in order to expose only the cam gear and whenever I wanted to make an adjustment, it was 15 minutes and I was ready for full on race mode...otherwise, this lumpy cam made for quite a tame traffic capable engine...Never lost a street race!
How you can put a hand on a lobe another on a journal and turn clockwise blows my mind, first hundred years of engine building cam was a solid piece of machined iron.
Variable Timing Electronic Control . . . . I think. Unless I'm wrong. anyway. Thank you for making these videos. You are as curious about the How and Why of automotive technology as I was when I went through Fords ASSET program in the '80s. I retired from turning wrenches in 2009, so I'm not 'up to speed' on the latest tech, and your explanations are well done and well researched. Plus, my world was all about Fords for three decades. anyway. Happy New Year to you and your loved ones from very cold Alaska (high today was -17°F)
Thank you very much! I definitely love the automotive field. Sometimes I wish it loved me back 😄. I know a few techs who work up there in Alaska, I always ask why they stay and their answers are the same every time, "they pay me too much to leave" 😂. I'm sure it's beautiful though!
I like that you pointed out this technology’s use in the Hemi is more for better emissions than it is for power gain. The fact that pre-2009 Hemi engine utilized an EGR system and the VVT engines do not serves to back this point up
Absolutely, like I mentioned it's a very robust design. I actually like the early Gen 3 hemi for how reliable they are. They don't make the power of the newer ones without a lot of help, but I've seen people mistreat them horribly and they still just work. 👍
Great work as usual, thank you! You mentioned the better emissions numbers being sort with this technology and that with a single cam we can only work the intake or exhaust (with a few exceptions) referring to the fact that this only works on the exhaust valves in the HEMI engine but as far as performance goes the increase and difference in numbers and overall effect when operating on the intake valves with VVT is monumentally greater than with the exhaust valves! Cheers
I didn't understand when the computer advance or retard the cam. My 96 Tahoe was getting 12 mpg. I was reading online and someone said a worn timing chain could cause my engine to burn gas. The engine did have over 285k miles. I replaced the timing chain and I had to advance the cam a little bit for the gear to bolt to the cam. The engine ran little raw @ low rpm but like a race engine @ high rpm. The intake valves were stay open a little too long and drinking gas. After the new timing chain and a little time for the pcm to adjust. My old 5.7 was getting 14.5 mpg again.
Thank you very much for the detailed explanations. Since I have the pleasure of driving a 2010 Dodge Charger with the Hemi 5.7 here in Germany, I am glad to have found your contributions on RU-vid. To my question: Based on the experience with Mercedes (SLK 230 / R170), which are also equipped with variable camshaft, the solenoid switches of the adjustment are leaking. As a result, oil leaks from the switch into the wiring harness. Due to the capillary effect, the oil creeps through the wiring harness into the engine control unit, where it can then lead to a short circuit. As a remedy, so-called oil stop cables have been developed, which are offered as a retrofit solution. Do we have a similar scenario with the HEMI engine with leaking solenoid switches on the camshaft?
Thank you very much for the quick response. I was a bit worried about that particular issue since Daimler was involved. Often it is very easy to use already existing solutions. Again thank you very much I appreciate your explanations on your Channel.
Such a bummer 😢. I get it though, he's tired of people on the internet second guessing everything he does instead of just appreciating it. He's in a spot now where he can get paid to continue doing what he's always done, but doesn't have to have the internet looking over his shoulder all day long. I think Woody will try his best, but it clearly won't be the same without Turbo Yoda.
Excellent video. I'm just wondering if you have a quick method to determine what engine has one and one that does not? For example I know my 3.0L chev engine has it as it is labelled as such, but not sure about my 09 6.1L Hemi and my 16 392 (which has MDS). Can they have both VVT and MDS or are they mutually exclusive? thanks
I have a question not about this great video. I know you were transmission expert my 2019 ram shifts hard from 4th to 3rd when downshifting sometimes it seems like the transmission will pop out of gear and tell me the shift it back into park then back into drivewhen I put the transmission manually in -8 it never happens. Most of the time it happens only when it’s cold and I’m stopping quickly.
@@ReignitedAuto man youtube is crap anymore, search for something, get a little of what you're looking for and a ton of random stuff. I believe it was called a Johnson bar.
Say I have a VVT 5.7L full stock@@ReignitedAuto, could I replace the cam with a 6.4L cam, and would it provide any gains? What else would I need to change? Valve springs?
@33ordie I do think the 6.4 cam gives a decent midrange bump without having to change too many other components. I actually did this swap in my budget challenger series I did a couple years ago. However, swapping the camshaft can be a significant amount of work and it might be better to maximize your results from doing so. This means going with a more aggressive camshaft, stiffer valve springs and a custom tune. More money no doubt, but much larger potential for gains. One thing to keep in mind, the camshaft cam only take advantage of more airflow if you've already modded the rest of the engine like the intake and exhaust.
I have a 08 jeep commander 5.7 I seen someone post a video that you can add hellcat oem cam to your 5.7, not sure if that means pre eagle. Since it has vvt. 🙏
VVT's have definitely made modern engines much less reliable. Engine such as the 4.6 modular with a basic overhead cam arrangement could often run 300 K miles. Engines with VVT's commonly only make it only 150K miles
This is just a quick note of thanks. I purchased at 2009 Challenger RT with low miles in October and VVT is a boogie man that has been looking over my shoulder ever since. You took some of the mystique out of that bad guy with your frank, down to earth explanation here. You can see how if you were sloppy with your oil changes and routine maintenance the poor flow of oil could easily come back to bite you. Very helpful.
VTEC - Variable Valve Timing and Lift Electronically Controlled.... An older technician told me this when I worked at a Honda dealership. Not sure if he was right because the letters don't quite add up, but i remember reading this on an old manual as well. The fact that I remember this lol
We have so many mentors in life that help us to learn. I had a pretty important one growing up 😉 Now it's my responsibility to mentor others when possible. Thank you for being a great example!
Great video Sky, was informative and easy to understand. Definitely would like to see a video about the MDS system. Look forward to more videos. I'm sure you haven't done anything on the magnum, but would be nice to get an update.
Definitely planning on doing a MDS video, was waiting to see if this one was well received first! Magnum content is incoming as well, HOPEFULLY the next episode will be out next saturday, I'm tearing down the blown up engine on Monday, ready to build the new upgraded engine 💪
VTEC - variable timing electronic control, advances the exhaust cam shaft, has a pressure switch for feedback… first used on Prelude, as I remember it…
I am sure you already know this, but the last gen viper had a mechadyne "cam in a cam" system that actually could vary the intake and exhaust independently. For those that thought the Viper engine was a tractor engine, it was one of the first single-cam engines to do that. I believe the new c8 engine also has a cam in a cam. Also, for those that are interested further, when you can adjust both intake and exhaust independent of another, you can get that "ghost cam" effect through tuning - basically all you are doing is increasing overlap.
I was actually going to insert a clip of that Viper cam just because it's interesting, but I thought it might distract too much from what I was trying to get across. Super neat tech though! 👍
@@jondoe4667 The valvetronic system is much more complex as it can control more than duration (It has to since it replaces the throttle body). In reality these systems are band-aids and only Koenigsegg's freevalve system can really control everything without cams, and can vary opening profiles without worry about the ramp wear, valve float, or spring pressure. I do not think they have ultimate valve closing ability because I think they rely on a spring to assist/dampen the closing so the valve doesn't beat itself into the head. But back to cams, the Hemi and Chevy "Cam in block" engines minimize complexity since there is a single phaser to deal with. Not to mention making for a small head (Well the Hemi is kind of big, but nowhere near DOHC-head big)
@@The3chordwonder yeah the video I had watched about the bmw ones were completely electronic I believe, and basically had infinite adjustability. To me it seemed really complex. I'd much rather have the simple GM or Mopar system.
Thanks! Very well done. You would be a good person to address the wide range of opinion on why 5W-20 is used and why other viscosities can alter the function.
Hi. Doesn't installing HV pump from Hellcat change the pressure on VVT fazer thus wrongly controls the faze? If i have for example 50% PWM signal of VVT valve doesn't it have different displacement with normal and Hellcat pump because of different pressures? Or is there any feedback signal from a fazer angle going to the controller, which compensate it?
Those tiny needle bearings are ridiculous. A simple roller on a single larger pin would increase the contact area between the roller and lifter body by approximately 100%
I'm getting read to install a cam in my 392 and you helped me a lot. Also on a different note i lost compression in cylinder 8 and after checking every thing out it turned out that one the plastic shot runners in the intake broke off and was holding my intake valve open. So if you could explain that on a video for people to check before pulling a head it would save them a lot of money. Thanks for all your videos.
Variable Valve Timing & Lift Electronic Control Vtec is good at making fast cars slow. Research Subaru's AVLS, & Fiat's FIRE, both are very different ways of doing the same thing…well, they do different things, but similar results.
A lot of manufacturers use VVT because it is more effective than EGR and allows them to do away with EGR. VVT is better for both gas mileage and power. Most engines are required to have either EGR or VVT for emissions reasons. I think some engines actually have both. The Ford 2.7 ecoboost I believe has both.
It sure doesn't LOOK like those phaser vanes have 30 degrees of rotation available. I would guess it looks like about 24 degrees. You could easily hold a protractor up against it and find out for sure, but 37 degrees looks impossible.
Great video man you answered my question about cam phase limiters and locks. Never knew why they wanted to get rid of it to make power now I know safety lol. Can’t you tell me who makes the best valve springs and rods for the 6.2 after market cam package with a limiter not lock. Or atleast the a good round about spec for a cam that works like stock down low but give good high end power. I can even deal with it being a bit sluggish down low. Also when selecting a cam shaft for the hc what is the optimal rpm cam. What’s safe to spin these motors to? Any info is welcome thank you. Excellent video as always man.
None that I'm aware of, I think even with the high volume pumps we are usually only running in the 75-85psi range which isn't a ton more than the factory pump makes at higher RPM. It might be an issue if you tried to run using 150psi, but even then I doubt it. 👍
I was reading comments to ask the same question. Appreciate the response, but I can't help to think it would alter the cam timing a bit more aggressively earlier in the RPM range. Maybe not significantly. Maybe ask Melling or an independent dyno to do a test? Would be fun to see the results.
@tbiker99 the pressure wouldn't have any effect on the amount of flow the solenoid is capable of at various PWM as far as I'm aware. Besides which, the cam sensor is constantly checking to verify the cam position relative to the crankshaft, so it would immediately set a code if it were trying to obtain a certain value and was unable to do so.
I forgot about the cam sensor. That does make sense, even if it did cause a difference the computer would adjust for it. Good call. thanks for the response. @@ReignitedAuto
Crazy that noone makes a replacement upper gear that's solid instead of adding another widget to lock out the VVT mechanism. I'd use that in a heartbeat!
I have a question I purchased the melling high volume oil pump I was getting informed by some mechanics that the high volume oil pump it can suck all the oil out of the pan .how true is that ?
That's actually a good question I'm not 100% sure. Unfortunately at the dealer level we can't get the reluctor wheel separate from the crankshaft so I don't have a part number to go off of. With that being said, I feel about 95% that they are the same.
Great job explaining the voodoo behind VVT. Are stock, oem grind Hemi cams the limit for unlocked VVT phaser, or is there a particular aftermarket grind that can still sqeeze more power but not need a vvt reduction/lockout mod.
That's actually a good question I'm not sure. I think every aftermarket cam I've seen has a least a VVT limiter needed. But I think as soon as you have a cam with any sort of higher lift it will require it.
Awesome video, it is great that you are taking the time to make videos like this, so many just talk past or over things like this. I have a number of G3's and know what VVT is but I have never seen the inside of one nor did I know it had a 37 deg swing, but most importantly I was unaware that the G3 is a interference engine. I guess I could have figured it out but never really thought about it until you mentioned it, thanks. Have a happy New Year!
Thanks again for sharing your knowledge openly & plainly for the masses - love it! One thing I think needs corrected - the VVT is in full advance by default, which you showed. This is the low-end mode. retarding the cam adds to the high-RPM capability & adds a few horsepower up high. if you lock it out, you''re getting rid of that extended RPM power, not limiting your torque. That is the same as non-VVT engines of all types - retard the cam install centerline, and it will soften the bottom end - advance the cam install centerline, and it will pull at a lower RPM into the torque range. Hopefully that helps?
It's true that the limiter locks the phaser in the advanced position, but the aftermarket camshaft you're installing is already taking this into account when they are grinding the cam, therefore when you install the cam it's already set up for higher rpm performance. If aftermarket came were only useful for bottom end gains I don't think you'd see too many people swapping them. 👍
